Dietary carbohydrates include foods that are rich in starch or sugar (or both). The chemical name for starch is polysaccharide (“poly” meaning many and “saccharide” meaning sugars). The many sugars that make up starch are linked by chemical bonds that are broken down by the body during the process of digestion. Starches are classified as complex carbohydrates and these can be part of a heart healthy diet.
One major sub-category of carbohydrates is simple carbohydrates, otherwise known as simple sugars. Simple sugars are one- or two-unit sugars (mono- or disaccharides) that are more quickly and easily digested and absorbed by the body. While this may sound like a good thing at first, eating too many simple sugars can have serious negative consequences for our health. We need to limit the amount of sugar in our diets to improve our heart health and prevent heart disease.
The simplest and most common of the simple sugars is glucose, a single-unit sugar that our bodies can break down to make energy or convert into body energy stores, including fat. A close relative of this sugar is fructose, the kind of sugar found in fruits, as well as many other foods. When glucose and fructose are linked together, they form the disaccharide called sucrose (another simple sugar), which is also known as table sugar. There are generally far too many simple sugars in the Western diet - which is gradually becoming the Global diet, as processed food becomes increasingly available around the world.
The pitfalls of a high-sugar diet
High-sugar diets have been linked to excess weight gain and an increased risk of developing Type 2 Diabetes, certain types of cancer and heart disease. Interestingly, when we reduce the sugar in our diets over a longer period of time, our taste buds become more sensitized to smaller amounts of sugar in our food. So, by eating less sugar, we actually end up needing less sugar to satisfy that sweet tooth! But beware: artificial sweeteners should also be avoided. Calorie-free artificial sweeteners, like those found in diet sodas, are so sweet that they tend to desensitize our taste buds, meaning that we may end up craving (and needing) more sugar to get the same sensation of sweet! But not all sugars are bad for us.
Naturally occurring sugars
Naturally occurring sugars (like those found in fruits and milk products) are generally much healthier for us because they’re complexed or bound together with other good nutrients, like fiber (in the case of fruit), protein and calcium (in the case of milk). Lactose is the disaccharide found in milk and dairy products. These foods can be an important part of a healthy diet when eaten in the right amounts…but remember: everything in moderation! Full fat dairy products are still rich in saturated fats, which can contribute to elevated cholesterol levels if eaten in excess. Take the middle road – if you like dairy, choose moderate amounts of low fat dairy products, like low fat milk, yoghurts, cottage cheese and other cheeses. Especially during periods of rapid growth like pregnancy or the teenage years, these nutrients can be an important part of a healthy diet.
Unlike the one- or two-unit sugars (simple carbohydrates), complex carbohydrates are made up of many glucose molecules linked together by chemical bonds. Starchy foods, including potatoes, bread, pasta, and rice are high in complex carbohydrates, but the degree to which these are “heart healthy” depends - mostly on how much fiber they contain.
How can fiber help to reduce cholesterol levels and protect heart health?
Dietary fiber is also a form of complex carbohydrate. The major difference is that dietary fiber contains little or no calories because our bodies cannot break down the bonds between the single sugar units in this kind of complex carbohydrate. Additionally, there are two subtypes of dietary fiber: 1) soluble fiber and 2) insoluble fiber.
What is soluble fiber and how can it support health?
Soluble fiber dissolves in water and can play an important part in lowering cholesterol levels because it inhibits the absorption of cholesterol back into the bloodstream. Soluble fiber can be found in foods like unprocessed oatmeal, oat bran, apples, prunes and some legumes, like kidney beans.
What is insoluble fiber and how can it support health?
Insoluble fiber absorbs water (like a sponge) and acts as a stool softener, speeding up the passage of food through the intestinal tract. This prevents constipation, a common problem in those who eat a diet that is high in refined (low-fiber) carbohydrates. Insoluble fiber is found in foods like wheat bran, lentils and flex seeds. Both types of fiber are found in fruits and vegetables.
What are the best carbohydrates for heart health?
In order to eat a heart healthy diet, the carbohydrates we choose should ideally be unrefined, to support intestinal health and maximize nutrient density. This means choosing whole-grain breads over white breads and brown rice over white rice whenever possible. Unrefined carbohydrates take longer to digest so they also sustain satiety, delaying the return of hunger and helping to stabilize blood sugar levels. All of these factors can lead to better general health - and a healthier heart.
By Maya Adam, MD, Adapted from Food, Love, Family, A Practical Guide to Child Nutrition